import { Injectable, NotFoundException } from '@nestjs/common';
import { ReviewRepository } from './review.repository';
import { ReviewCardGenerationWorkflow } from '../ai/workflows/review-card-generation.workflow';
import { SubmitReviewDto } from './dto/submit-review.dto';

@Injectable()
export class ReviewService {
  constructor(
    private readonly reviewRepository: ReviewRepository,
    private readonly cardGenerationWorkflow: ReviewCardGenerationWorkflow,
  ) {}

  async getDueCards(userId: string) {
    return this.reviewRepository.findDueCards(userId);
  }

  async submitReview(userId: string, id: string, dto: SubmitReviewDto) {
    const card = await this.reviewRepository.findById(id);
    if (!card) throw new NotFoundException(`Review card ${id} not found`);
    const log = await this.reviewRepository.insertLog({
      userId,
      reviewCardId: id,
      rating: dto.rating,
      responseText: dto.responseText,
    });
    await this.reviewRepository.updateCard(id, {
      status: 'reviewed',
      nextReviewAt: new Date(Date.now() + 86400000),
    });
    return log;
  }

  async generateCards(userId: string, input: {
    knowledgeItemTitle: string;
    knowledgeItemContent: string;
    cardCount?: number;
  }) {
    const result = await this.cardGenerationWorkflow.execute({
      userId,
      knowledgeItemTitle: input.knowledgeItemTitle,
      knowledgeItemContent: input.knowledgeItemContent,
      cardCount: input.cardCount,
    });

    const savedCards: any[] = [];
    for (const card of result.cards) {
      const saved = await this.reviewRepository.insertCard({
        userId,
        frontText: card.frontText,
        backText: card.backText,
        difficulty: card.difficulty,
        status: 'active',
        intervalDays: 1,
        easeFactor: 2.5,
        repetitionCount: 0,
        lapseCount: 0,
        nextReviewAt: new Date(),
      });
      savedCards.push(saved);
    }

    return { cards: savedCards, totalCount: result.totalCount };
  }
}